\documentclass{article}

\begin{document}
\begin{tabular}{|c|c|c|c|c|}
	\hline
	A & 1 & \multicolumn{2}{c|}{2}                  &   \\ \hline
	B & \multicolumn{2}{c|}{2} & 1                  &   \\
	\hline
	a & b & c                  & d                  & e \\
	\hline
\end{tabular}

\bigskip

\begin{tabular}{|c|c|c|c|c|}
	\hline
	A     & 1 & \multicolumn{2}{c|}{2}                   & \\ \hline
	B     & \multicolumn{2}{c|}{2} & 1                   & \\
	\hline
	\omit &   &                    &                     &
\end{tabular}

\end{document}
